Synthetic approaches to radiochemical probes for imaging of bacterial infections.

This present review provides an account on the available synthetic strategies employed to radiolabel commercial and potential bacteria-selective probes for tomographic imaging. These molecular probes encompass leukocytes, antibodies, small molecules, peptides, antibiotics, macrolides, vitamins, oligomers and siderophores. Although this technique has shown to be a valuable tool for non-invasive infection imaging, more development is required to create easy-to-radiolabel kit solutions/procedures for the preparation of the probes.

Synthesis, in vitro evaluation, and 68 Ga-radiolabeling of CDP1 toward PET/CT imaging of bacterial infection.

Bacterial infections are a major concern in the human health sector due to poor diagnosis and development of multidrug-resistant strains. PET/CT provides a means for the non-invasive detection and localization of the infectious foci; however, the radiotracers available are either cumbersome to prepare or their exact contribution toward the imaging is not yet established. Human antimicrobial peptides are of interest for development as PET radiotracers as they are an integral component of the immune system, non-immunogenic toward the recipient, and show selectivity toward pathogens such as bacteria. Herein we report on the potential of LL37, a human cathelicidin antimicrobial peptide, as a radiotracer for bacterial imaging. Bifunctional chelator 1,4,7-triazacyclononane,1-glutaric acid-4,7-acetic acid was utilized to functionalize the antimicrobial peptide, which in turn was capable of chelating gallium. The synthesized nat Ga-CDP1 showed bacterial selectivity and low affinity toward hepatic cells, which are favorable characteristics for further preclinical application.